Commit | Line | Data |
---|---|---|
67c5b804 MD |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
15f672f9 | 3 | * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
67c5b804 | 4 | * |
15f672f9 MD |
5 | * This library is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU Lesser General Public | |
7 | * License as published by the Free Software Foundation; only | |
8 | * version 2.1 of the License. | |
9 | * | |
10 | * This library is distributed in the hope that it will be useful, | |
67c5b804 | 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
15f672f9 MD |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | * Lesser General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU Lesser General Public | |
16 | * License along with this library; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
67c5b804 MD |
18 | */ |
19 | ||
20 | #define _GNU_SOURCE | |
21 | #include <limits.h> | |
22 | #include <stdio.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <sys/socket.h> | |
26 | #include <sys/stat.h> | |
27 | #include <sys/types.h> | |
28 | #include <sys/un.h> | |
29 | #include <unistd.h> | |
30 | #include <assert.h> | |
57773204 | 31 | #include <errno.h> |
11ba4bcb | 32 | #include <fcntl.h> |
67c5b804 | 33 | |
b728d87e | 34 | #include <ust-comm.h> |
7bc53e94 MD |
35 | #include <lttng/ust-error.h> |
36 | ||
37 | #define USTCOMM_CODE_OFFSET(code) \ | |
38 | (code == LTTNG_UST_OK ? 0 : (code - LTTNG_UST_ERR + 1)) | |
67c5b804 MD |
39 | |
40 | /* | |
41 | * Human readable error message. | |
42 | */ | |
57773204 | 43 | static const char *ustcomm_readable_code[] = { |
7bc53e94 MD |
44 | [ USTCOMM_CODE_OFFSET(LTTNG_UST_OK) ] = "Success", |
45 | [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR) ] = "Unknown error", | |
46 | [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOENT) ] = "No entry", | |
67c5b804 MD |
47 | }; |
48 | ||
49 | /* | |
7bc53e94 | 50 | * lttng_ust_strerror |
67c5b804 | 51 | * |
7bc53e94 MD |
52 | * Receives positive error value. |
53 | * Return ptr to string representing a human readable | |
54 | * error code from the ustcomm_return_code enum. | |
67c5b804 | 55 | */ |
7bc53e94 | 56 | const char *lttng_ust_strerror(int code) |
67c5b804 | 57 | { |
7bc53e94 MD |
58 | if (code == LTTNG_UST_OK) |
59 | return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)]; | |
60 | if (code < LTTNG_UST_ERR) | |
61 | return strerror(code); | |
62 | if (code >= LTTNG_UST_ERR_NR) | |
63 | code = LTTNG_UST_ERR; | |
64 | return ustcomm_readable_code[USTCOMM_CODE_OFFSET(code)]; | |
65 | ||
67c5b804 MD |
66 | } |
67 | ||
68 | /* | |
57773204 | 69 | * ustcomm_connect_unix_sock |
67c5b804 MD |
70 | * |
71 | * Connect to unix socket using the path name. | |
72 | */ | |
57773204 | 73 | int ustcomm_connect_unix_sock(const char *pathname) |
67c5b804 MD |
74 | { |
75 | struct sockaddr_un sun; | |
7bc53e94 | 76 | int fd, ret; |
67c5b804 | 77 | |
204d45df MD |
78 | /* |
79 | * libust threads require the close-on-exec flag for all | |
80 | * resources so it does not leak file descriptors upon exec. | |
81 | */ | |
11ba4bcb | 82 | fd = socket(PF_UNIX, SOCK_STREAM, 0); |
67c5b804 MD |
83 | if (fd < 0) { |
84 | perror("socket"); | |
7bc53e94 | 85 | ret = -errno; |
67c5b804 MD |
86 | goto error; |
87 | } | |
11ba4bcb MD |
88 | ret = fcntl(fd, F_SETFD, FD_CLOEXEC); |
89 | if (ret < 0) { | |
90 | perror("fcntl"); | |
7bc53e94 | 91 | ret = -errno; |
11ba4bcb MD |
92 | goto error_fcntl; |
93 | } | |
67c5b804 MD |
94 | |
95 | memset(&sun, 0, sizeof(sun)); | |
96 | sun.sun_family = AF_UNIX; | |
97 | strncpy(sun.sun_path, pathname, sizeof(sun.sun_path)); | |
98 | sun.sun_path[sizeof(sun.sun_path) - 1] = '\0'; | |
99 | ||
100 | ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun)); | |
101 | if (ret < 0) { | |
102 | /* | |
103 | * Don't print message on connect error, because connect | |
104 | * is used in normal execution to detect if sessiond is | |
105 | * alive. | |
106 | */ | |
7bc53e94 | 107 | ret = -errno; |
67c5b804 MD |
108 | goto error_connect; |
109 | } | |
110 | ||
111 | return fd; | |
112 | ||
113 | error_connect: | |
11ba4bcb | 114 | error_fcntl: |
7bc53e94 MD |
115 | { |
116 | int closeret; | |
117 | ||
118 | closeret = close(fd); | |
119 | if (closeret) | |
120 | perror("close"); | |
121 | } | |
67c5b804 MD |
122 | error: |
123 | return ret; | |
124 | } | |
125 | ||
126 | /* | |
57773204 | 127 | * ustcomm_accept_unix_sock |
67c5b804 MD |
128 | * |
129 | * Do an accept(2) on the sock and return the | |
130 | * new file descriptor. The socket MUST be bind(2) before. | |
131 | */ | |
57773204 | 132 | int ustcomm_accept_unix_sock(int sock) |
67c5b804 MD |
133 | { |
134 | int new_fd; | |
135 | struct sockaddr_un sun; | |
136 | socklen_t len = 0; | |
137 | ||
138 | /* Blocking call */ | |
139 | new_fd = accept(sock, (struct sockaddr *) &sun, &len); | |
140 | if (new_fd < 0) { | |
141 | perror("accept"); | |
7bc53e94 | 142 | return -errno; |
67c5b804 | 143 | } |
67c5b804 | 144 | return new_fd; |
67c5b804 MD |
145 | } |
146 | ||
147 | /* | |
57773204 | 148 | * ustcomm_create_unix_sock |
67c5b804 MD |
149 | * |
150 | * Creates a AF_UNIX local socket using pathname | |
151 | * bind the socket upon creation and return the fd. | |
152 | */ | |
57773204 | 153 | int ustcomm_create_unix_sock(const char *pathname) |
67c5b804 MD |
154 | { |
155 | struct sockaddr_un sun; | |
7bc53e94 | 156 | int fd, ret; |
67c5b804 MD |
157 | |
158 | /* Create server socket */ | |
159 | if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) { | |
160 | perror("socket"); | |
7bc53e94 | 161 | ret = -errno; |
67c5b804 MD |
162 | goto error; |
163 | } | |
164 | ||
165 | memset(&sun, 0, sizeof(sun)); | |
166 | sun.sun_family = AF_UNIX; | |
167 | strncpy(sun.sun_path, pathname, sizeof(sun.sun_path)); | |
168 | sun.sun_path[sizeof(sun.sun_path) - 1] = '\0'; | |
169 | ||
170 | /* Unlink the old file if present */ | |
171 | (void) unlink(pathname); | |
172 | ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun)); | |
173 | if (ret < 0) { | |
174 | perror("bind"); | |
7bc53e94 MD |
175 | ret = -errno; |
176 | goto error_close; | |
67c5b804 MD |
177 | } |
178 | ||
179 | return fd; | |
180 | ||
7bc53e94 MD |
181 | error_close: |
182 | { | |
183 | int closeret; | |
184 | ||
185 | closeret = close(fd); | |
186 | if (closeret) { | |
187 | perror("close"); | |
188 | } | |
189 | } | |
67c5b804 MD |
190 | error: |
191 | return ret; | |
192 | } | |
193 | ||
194 | /* | |
57773204 | 195 | * ustcomm_listen_unix_sock |
67c5b804 | 196 | * |
e41474be | 197 | * Make the socket listen using LTTNG_UST_COMM_MAX_LISTEN. |
67c5b804 | 198 | */ |
57773204 | 199 | int ustcomm_listen_unix_sock(int sock) |
67c5b804 MD |
200 | { |
201 | int ret; | |
202 | ||
e41474be | 203 | ret = listen(sock, LTTNG_UST_COMM_MAX_LISTEN); |
67c5b804 | 204 | if (ret < 0) { |
7bc53e94 | 205 | ret = -errno; |
67c5b804 MD |
206 | perror("listen"); |
207 | } | |
208 | ||
209 | return ret; | |
210 | } | |
211 | ||
212 | /* | |
57773204 | 213 | * ustcomm_recv_unix_sock |
67c5b804 MD |
214 | * |
215 | * Receive data of size len in put that data into | |
216 | * the buf param. Using recvmsg API. | |
217 | * Return the size of received data. | |
218 | */ | |
57773204 | 219 | ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len) |
67c5b804 | 220 | { |
913b87f1 | 221 | struct msghdr msg; |
67c5b804 | 222 | struct iovec iov[1]; |
7bc53e94 | 223 | ssize_t ret; |
67c5b804 | 224 | |
913b87f1 MD |
225 | memset(&msg, 0, sizeof(msg)); |
226 | ||
67c5b804 MD |
227 | iov[0].iov_base = buf; |
228 | iov[0].iov_len = len; | |
229 | msg.msg_iov = iov; | |
230 | msg.msg_iovlen = 1; | |
231 | ||
7e3cfcbe MD |
232 | do { |
233 | ret = recvmsg(sock, &msg, 0); | |
234 | } while (ret < 0 && errno == EINTR); | |
7bc53e94 MD |
235 | |
236 | if (ret < 0) { | |
237 | int shutret; | |
238 | ||
239 | if (errno != EPIPE) | |
240 | perror("recvmsg"); | |
241 | ret = -errno; | |
242 | ||
243 | shutret = shutdown(sock, SHUT_RDWR); | |
244 | if (shutret) | |
245 | fprintf(stderr, "Socket shutdown error"); | |
67c5b804 MD |
246 | } |
247 | ||
248 | return ret; | |
249 | } | |
250 | ||
251 | /* | |
57773204 | 252 | * ustcomm_send_unix_sock |
67c5b804 MD |
253 | * |
254 | * Send buf data of size len. Using sendmsg API. | |
255 | * Return the size of sent data. | |
256 | */ | |
57773204 | 257 | ssize_t ustcomm_send_unix_sock(int sock, void *buf, size_t len) |
67c5b804 | 258 | { |
913b87f1 | 259 | struct msghdr msg; |
67c5b804 | 260 | struct iovec iov[1]; |
7bc53e94 | 261 | ssize_t ret; |
67c5b804 | 262 | |
913b87f1 MD |
263 | memset(&msg, 0, sizeof(msg)); |
264 | ||
67c5b804 MD |
265 | iov[0].iov_base = buf; |
266 | iov[0].iov_len = len; | |
267 | msg.msg_iov = iov; | |
268 | msg.msg_iovlen = 1; | |
269 | ||
1ea11eab MD |
270 | /* |
271 | * Using the MSG_NOSIGNAL when sending data from sessiond to | |
272 | * libust, so libust does not receive an unhandled SIGPIPE or | |
273 | * SIGURG. The sessiond receiver side can be made more resilient | |
274 | * by ignoring SIGPIPE, but we don't have this luxury on the | |
275 | * libust side. | |
276 | */ | |
51d9d699 MD |
277 | do { |
278 | ret = sendmsg(sock, &msg, MSG_NOSIGNAL); | |
279 | } while (ret < 0 && errno == EINTR); | |
7bc53e94 MD |
280 | |
281 | if (ret < 0) { | |
282 | int shutret; | |
283 | ||
284 | if (errno != EPIPE) | |
285 | perror("recvmsg"); | |
286 | ret = -errno; | |
287 | ||
288 | shutret = shutdown(sock, SHUT_RDWR); | |
289 | if (shutret) | |
290 | fprintf(stderr, "Socket shutdown error"); | |
67c5b804 MD |
291 | } |
292 | ||
293 | return ret; | |
294 | } | |
295 | ||
296 | /* | |
57773204 | 297 | * ustcomm_close_unix_sock |
67c5b804 MD |
298 | * |
299 | * Shutdown cleanly a unix socket. | |
300 | */ | |
57773204 | 301 | int ustcomm_close_unix_sock(int sock) |
67c5b804 MD |
302 | { |
303 | int ret; | |
304 | ||
e6973a89 | 305 | ret = close(sock); |
67c5b804 | 306 | if (ret < 0) { |
e6973a89 | 307 | perror("close"); |
7bc53e94 | 308 | ret = -errno; |
67c5b804 MD |
309 | } |
310 | ||
311 | return ret; | |
312 | } | |
313 | ||
314 | /* | |
57773204 | 315 | * ustcomm_send_fds_unix_sock |
67c5b804 MD |
316 | * |
317 | * Send multiple fds on a unix socket. | |
318 | */ | |
57773204 | 319 | ssize_t ustcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, size_t len) |
67c5b804 | 320 | { |
913b87f1 | 321 | struct msghdr msg; |
67c5b804 MD |
322 | struct cmsghdr *cmptr; |
323 | struct iovec iov[1]; | |
324 | ssize_t ret = -1; | |
325 | unsigned int sizeof_fds = nb_fd * sizeof(int); | |
326 | char tmp[CMSG_SPACE(sizeof_fds)]; | |
327 | ||
913b87f1 MD |
328 | memset(&msg, 0, sizeof(msg)); |
329 | ||
67c5b804 | 330 | /* |
7bc53e94 | 331 | * Note: we currently only support sending a single FD per |
67c5b804 MD |
332 | * message. |
333 | */ | |
334 | assert(nb_fd == 1); | |
335 | ||
336 | msg.msg_control = (caddr_t)tmp; | |
337 | msg.msg_controllen = CMSG_LEN(sizeof_fds); | |
338 | ||
339 | cmptr = CMSG_FIRSTHDR(&msg); | |
340 | cmptr->cmsg_level = SOL_SOCKET; | |
341 | cmptr->cmsg_type = SCM_RIGHTS; | |
342 | cmptr->cmsg_len = CMSG_LEN(sizeof_fds); | |
343 | memcpy(CMSG_DATA(cmptr), fds, sizeof_fds); | |
344 | /* Sum of the length of all control messages in the buffer: */ | |
345 | msg.msg_controllen = cmptr->cmsg_len; | |
346 | ||
347 | iov[0].iov_base = buf; | |
348 | iov[0].iov_len = len; | |
349 | msg.msg_iov = iov; | |
350 | msg.msg_iovlen = 1; | |
351 | ||
51d9d699 MD |
352 | do { |
353 | ret = sendmsg(sock, &msg, MSG_NOSIGNAL); | |
354 | } while (ret < 0 && errno == EINTR); | |
7bc53e94 MD |
355 | |
356 | if (ret < 0) { | |
357 | int shutret; | |
358 | ||
359 | if (errno != EPIPE) | |
360 | perror("recvmsg"); | |
361 | ret = -errno; | |
362 | ||
363 | shutret = shutdown(sock, SHUT_RDWR); | |
364 | if (shutret) | |
365 | fprintf(stderr, "Socket shutdown error"); | |
67c5b804 MD |
366 | } |
367 | ||
368 | return ret; | |
369 | } | |
57773204 MD |
370 | |
371 | int ustcomm_send_app_msg(int sock, struct ustcomm_ust_msg *lum) | |
372 | { | |
373 | ssize_t len; | |
374 | ||
375 | len = ustcomm_send_unix_sock(sock, lum, sizeof(*lum)); | |
376 | switch (len) { | |
377 | case sizeof(*lum): | |
57773204 | 378 | break; |
57773204 | 379 | default: |
7bc53e94 MD |
380 | if (len < 0) { |
381 | if (len == -ECONNRESET) | |
382 | fprintf(stderr, "remote end closed connection\n"); | |
383 | return len; | |
384 | } else { | |
385 | fprintf(stderr, "incorrect message size: %zd\n", len); | |
386 | return -EINVAL; | |
387 | } | |
57773204 MD |
388 | } |
389 | return 0; | |
390 | } | |
391 | ||
392 | int ustcomm_recv_app_reply(int sock, struct ustcomm_ust_reply *lur, | |
393 | uint32_t expected_handle, uint32_t expected_cmd) | |
394 | { | |
395 | ssize_t len; | |
396 | ||
397 | memset(lur, 0, sizeof(*lur)); | |
398 | len = ustcomm_recv_unix_sock(sock, lur, sizeof(*lur)); | |
399 | switch (len) { | |
400 | case 0: /* orderly shutdown */ | |
57773204 MD |
401 | return -EINVAL; |
402 | case sizeof(*lur): | |
57773204 | 403 | if (lur->handle != expected_handle) { |
c1ee6c90 | 404 | fprintf(stderr, "Unexpected result message handle\n"); |
57773204 MD |
405 | return -EINVAL; |
406 | } | |
57773204 | 407 | if (lur->cmd != expected_cmd) { |
c1ee6c90 | 408 | fprintf(stderr, "Unexpected result message command\n"); |
57773204 MD |
409 | return -EINVAL; |
410 | } | |
7bc53e94 | 411 | return lur->ret_code; |
57773204 | 412 | default: |
7bc53e94 MD |
413 | if (len < 0) { |
414 | /* Transport level error */ | |
415 | if (len == -ECONNRESET) | |
416 | fprintf(stderr, "remote end closed connection\n"); | |
417 | return len; | |
418 | } else { | |
419 | fprintf(stderr, "incorrect message size: %zd\n", len); | |
420 | return len; | |
421 | } | |
57773204 MD |
422 | } |
423 | } | |
424 | ||
425 | int ustcomm_send_app_cmd(int sock, | |
426 | struct ustcomm_ust_msg *lum, | |
427 | struct ustcomm_ust_reply *lur) | |
428 | { | |
429 | int ret; | |
430 | ||
431 | ret = ustcomm_send_app_msg(sock, lum); | |
432 | if (ret) | |
433 | return ret; | |
7bc53e94 | 434 | return ustcomm_recv_app_reply(sock, lur, lum->handle, lum->cmd); |
57773204 MD |
435 | } |
436 | ||
57773204 MD |
437 | /* |
438 | * Receives a single fd from socket. | |
439 | * | |
7bc53e94 MD |
440 | * Returns negative error value on error, or file descriptor number on |
441 | * success. | |
57773204 MD |
442 | */ |
443 | int ustcomm_recv_fd(int sock) | |
444 | { | |
445 | struct iovec iov[1]; | |
446 | int ret = 0; | |
447 | int data_fd; | |
448 | struct cmsghdr *cmsg; | |
449 | char recv_fd[CMSG_SPACE(sizeof(int))]; | |
913b87f1 | 450 | struct msghdr msg; |
57773204 MD |
451 | union { |
452 | unsigned char vc[4]; | |
453 | int vi; | |
454 | } tmp; | |
455 | int i; | |
456 | ||
913b87f1 MD |
457 | memset(&msg, 0, sizeof(msg)); |
458 | ||
57773204 MD |
459 | /* Prepare to receive the structures */ |
460 | iov[0].iov_base = &data_fd; | |
461 | iov[0].iov_len = sizeof(data_fd); | |
462 | msg.msg_iov = iov; | |
463 | msg.msg_iovlen = 1; | |
464 | msg.msg_control = recv_fd; | |
465 | msg.msg_controllen = sizeof(recv_fd); | |
466 | ||
7e3cfcbe MD |
467 | do { |
468 | ret = recvmsg(sock, &msg, 0); | |
469 | } while (ret < 0 && errno == EINTR); | |
470 | if (ret < 0) { | |
45d35b9f MD |
471 | if (errno != EPIPE) { |
472 | perror("recvmsg"); | |
473 | } | |
7bc53e94 | 474 | ret = -errno; |
57773204 MD |
475 | goto end; |
476 | } | |
477 | if (ret != sizeof(data_fd)) { | |
7210fb23 | 478 | fprintf(stderr, "Received %d bytes, expected %zd", ret, sizeof(data_fd)); |
7bc53e94 | 479 | ret = -EINVAL; |
57773204 MD |
480 | goto end; |
481 | } | |
482 | cmsg = CMSG_FIRSTHDR(&msg); | |
483 | if (!cmsg) { | |
c1ee6c90 | 484 | fprintf(stderr, "Invalid control message header\n"); |
7bc53e94 | 485 | ret = -EINVAL; |
57773204 MD |
486 | goto end; |
487 | } | |
488 | if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) { | |
c1ee6c90 | 489 | fprintf(stderr, "Didn't received any fd\n"); |
7bc53e94 | 490 | ret = -EINVAL; |
57773204 MD |
491 | goto end; |
492 | } | |
493 | /* this is our fd */ | |
494 | for (i = 0; i < sizeof(int); i++) | |
495 | tmp.vc[i] = CMSG_DATA(cmsg)[i]; | |
496 | ret = tmp.vi; | |
e55f988e MD |
497 | /* |
498 | * Useful for fd leak debug. | |
499 | * fprintf(stderr, "received fd %d\n", ret); | |
500 | */ | |
57773204 | 501 | end: |
7bc53e94 MD |
502 | if (ret < 0) { |
503 | int shutret; | |
504 | ||
505 | shutret = shutdown(sock, SHUT_RDWR); | |
506 | if (shutret) | |
507 | fprintf(stderr, "Socket shutdown error"); | |
508 | } | |
57773204 MD |
509 | return ret; |
510 | } |